Experts Question Benefits of Gluten-Free for All but a Small Minority

A decade ago, few Americans had heard of gluten. Today, one survey says, almost a third are trying to avoid the element found in grain. In growing numbers, the world's biggest food makers and restaurant chains are retooling recipes and labels to tap into the concern, creating a multibillion-dollar business out of gluten-free products.

The trend caught the eye of Heather Nutsch, an oncology researcher in Omaha, Neb., who has struggled with her weight for years. In February, she decided to try a gluten-free diet after a...